Sanofi embarks on Zika vaccine hunt

Begins research programme as WHO declares the virus a global emergency

Sanofi's vaccine division has started an R&D programme to try to find a vaccine against the Zika virus, which has been called a 'global emergency' by the World Health Organization (WHO).

The virus - which may be linked to a cluster of microcephaly and other neurological disorders such as Guillain-Barré Syndrome (GBS) in Brazil - is "a public health threat to other parts of the world", according to WHO Director-General Margaret Chan.

The agency debated the latest outbreak in Brazil at an emergency committee meeting yesterday and said the priority is to protect pregnant women and their babies from the virus and to control the Aedes mosquitoes that spread the disease.

Sanofi Pasteur said that it would draw on experience in developing vaccines for similar viruses such as yellow fever, Japanese encephalitis and dengue to accelerate the search for a Zika vaccine. The company secured regulatory approval for the first dengue vaccine - Dengvaxia - last year.

Like dengue, Zika virus (ZIKV) is a member of the Flavivirus genus - which includes a number of viruses that are spread by insect vectors and cause encephalitis.

Sanofi Pasteur said its experience with dengue "can be rapidly leveraged to help understand the spread of ZIKV and potentially speed identification of a vaccine candidate for further clinical development".

While it has not been proven that Zika causes microcephaly and GBS, Chan said medical experts and WHO advisors "agreed that a causal relationship … is strongly suspected".

Normally a rare condition, microcephaly results in an abnormally small head impairing brain development, and there has been a cluster of 4,000 cases in Brazil since the start of 2015.

Patterns of recent spread and the broad geographical distribution of mosquito species that can transmit the virus, as well as the lack of vaccines and rapid and reliable diagnostic tests, and the absence of population immunity in newly affected countries were cited as major causes for concern.

"Sanofi Pasteur is responding to the global call to action to develop a Zika vaccine given the disease's rapid spread and possible medical complications," said Nicholas Jackson, Sanofi Pasteur's global head of research.

GlaxoSmithKline (GSK) has also reportedly started early work on a ZIKV vaccine, while researchers at the US National Institutes of Health (NIH) are looking at DNA- and live virus-based candidates.